Tree Bumblebee (B. hypnorum) 2014 Notes

I’m hoping this “Topic” will allow us to keep together our Tree Bumblebee Discussion notes for 2014.
We’ve used the same approach in previous years and by and large it has worked quite well.

Thanks to Elaine for the prompt for me to set it up !

Tree Bumblebees are a special interest of mine, but information about them is difficult to find in the regular bumblebee books - because it is too new to the UK.

If we can use the Forum to keep useful information about the species together, then it will hopefully become of wider use.

Yours Clive

PS.
I’ve been seeing B. hypnorum queens around since early this month. Look out for them foraging on Pussy Willow trees and Winter Heathers, Blackcurrant and Gooseberry bushes; Apple, Cherry and Plum trees. Also Sunning and Nest Searching - which they frequently do along vertical surfaces, sometimes several metres above the ground.

Here’s a picture of a queen working a Prunus bush for Nectar.
Also another of a queen sunning on an old plastic sack on some wasteground.

Image Attachments

Interested to see your topic on B.hypnorum.
Last year I saw the odd worker hypnorum foraging in my garden. This year I have seen a number of queens and I am now lucky enough to have a queen nesting in a bird box. I first observed her entering the nest box on 17 March and she is still active. Yesterday I observed another hypnorum queen nest searching around this bird box, trying her hardest to get into the box. Although she flew up to the entrance I didn’t observe her go in. She may well have been successful in entering the box by now. I presumed she may have been attracted either to the bird nest smell or the smell of the other queen, and may well have been attempting to usurp the original queen (?).
Today the weather has warmed up a little and noticed two hypnorum queens in my garden, one nest searching along there guttering and eaves of our bungalow and another flying around an oak tree in the garden.
This is the first year I have seen queens in my garden (Carmarthenshire). Will keep you posted on the queen in the bird box.

It is amazingly lucky that you spotted these queens using the nest box.

Might you be able to make something like a daily / weekly log about what you observe over the coming weeks and months ?

Back in 2009 I too had a natural colony in a bird box in my garden.
The first thing I noticed was a queen carrying pollen into the nest box, so I knew she had started to set up home.
Despite keeping an eye out for activity, it was not until there was a drone cloud outside the box many weeks later that I saw any further activity.
Later I logged what I knew, which was surprisingly little !

Have a look at the information below - and see if you can prepare yourself for coming events !

I keep a log/diary for the year which includes all my Bombus activities and sightings and any box occupations I have.
I had B.hypnorum activity today - The queen in the bird box still seen going in and out during the day. Also saw another hypnorum queen and she was nest searching around some schwegler boxes. She entered both boxes, one of which was occupied by a B.terrestris queen (not sure if this queen is now in the box). The way she flew to the boxes, especially the first, led me to believe that she may well have visited before. Was she trying to usurp the terrestris queen. I know terrestris queens will usurp other queens, any idea about hypnorum ?

Later on in the day I saw a hypnorum queen nest searching along the eaves of the shed as well as entering a bag of compost which was partly open. This may well have been the same queen from earlier.

Gosh, you are wonderfully well organised !
I have a little spiral bound notebook I fill in daily, but for most topics data is not sequenced to a specific topic.

In what follows I’m working from my aged memory, so if it is not quite correct, just have a play !

To add photos you post your main text.
Then you select Edit.
In edit (down the page) you have an options of “Choose File”.
Do that and select the photo you want to add.
Then press Update Post.

Photos are very restricted in file size. You can have up to 3 photos, but with a maximum combined (or single) file size of 300 Kb.
I think you can add two photos at one edit session.
My routine is to find the photos separately, then export them to a temporary holding location, choosing reduced file size.
Then check if it is small enough to be acceptable. Then proceed as above.
But you’ll have to have a play with your own photo store.
Do have a go, because pictures do liven up our posts !

The B.hypnorum queen in my bird box is still active. Saw her leave and enter the box several times today. A lot more queen activity today due to the rain stopping and the sun coming out.
I would expect workers to hatch out soon in this nest if my calculations are right.

I also have a B.hypnorum queen flying around over the last week or so going into a couple of schwegler bee boxes I have in the garden. A queen was checking out a box today, but they (or it maybe the same one) do not seem to have set up a nest in any.
Will keep you posted if workers are observed in the bird box.

This is my first post - hope I get this right.
Have seen a tree BB three times now in the past two weeks here in Devon. I think I may have seen one last year but am not sure.

Hi Adoxa,

Welcome to the Forum.
Once you get your eye in, Tree Bumblebees are remarkably common.
The queens can vary quite a bit in size; and some will be noticeably darker than the standard ones.
At this time of year keep an eye on Winter Heathers, Cherry and Apple blossom and other fairly shallow flowers.

I’ve got a thread running in the “Gardening Zone” asking for comments on what flowers they work.
Any extra flower types = useful data !

Just to inform you that the B.hypnorum nest in the bird box now has workers. I saw a couple leaving and re-entering the nest, along with the queen who is still foraging. I expect her to continue until worker numbers increase a bit. A worker was seen feeding on Lungwort.
These are first workers I have seen this season, along with a B.pratorum feeding at a piers.

As mentioned above the B.hypnorum nest box now has active workers.
On saturday 12 Apr I observed some interesting behaviour at the entrance to the box.

For the last couple of weeks I have had another hypnorum queen flying around the nest box and seemingly trying to get into the nest through gaps etc.
At about 7:30 pm I noticed a queen flying around the nest box. I was hoping to catch this queen to identify her as although she had a bright white tail she looked almost black all over. I didn’t manage to catch her but noticed she was a hypnorum but her thorax was extremely dark and it was difficult to see the gingery hairs, although they were there. She then entered the box. After about two minutes she flew out of the box being pursued by the original queen, who went straight back in the nest. the dark queen flew off.
Some 10 minutes later the dark queen came back and entered the box, and about 30/40 seconds after she had entered another hypnorum queen (normal colour) entered the box !
After ten or so minutes a queen was seen flying out of the box , but which queen, was unknown.

Today about 6:30pm I saw a queen leave this box. She didn’t go straight out as the ‘original’ queen does but flew briefly around entrance before leaving. She returned in ten minutes and landed on the entrance tube. A worker came out and ‘attacked’ her, knocking her down into a bush below. She went up into the tree and rested for 5 minutes- she then returned and entered the nest box.

My theory is that these two queens seem to be trying to ‘take over’ or usurp the original queen. There has been at least one hypnorum queen hanging around the oak tree where the nest box is for two maybe more weeks and i have noticed the very dark queen for a little less.
I have never noticed the ‘intruder’ queens enter the nest box before, but as soon as workers are active they are going in - maybe pure coincidence, i do not know. Do they wait for active workers to be present so that they have less work/foraging to do if one succeeds in taking over ?
Unfortunately as the queens are not marked it is difficult to identify which is which, except the dark one. Did not see the dark form today.
Not very scientific and all theories but fascinating none the less. Hope the original queen can stick it out !
I would love to know if anyone else has observed any thing similar to these observations ?

I’ve just noticed this morning 16-5-2014 that we seem to have Tree Bumblebees entering our loft space in our bungalow (Hatfield, Herts) between the gutter and roof tile over hang.
Initial observations, that 2-3 at the most 4 seem to hang around outside swirling by the gutter, as others return or depart they seem to relieve each other like they are on guard. Quite amazing to watch.
I’m guessing that the queen is in the loft. I’ve not ventured up there primarily because I don’t wish to disturb them, and space is a bit tight.

Earlier today I found a ‘big’ Tree Bumblebee (possibly a queen) that had flown into our greenhouse, so I allowed it to walk onto my hand and found a tree branch in the garden for it to vacate my hand and live on. Am I right to assume this ‘possible queen’ is not part of the colony in th loft space?
Those entering the roof area are frequently visiting our Azaleas, Cotoneaster, and flowering Hawthorns in the garden.

The funny thing is for ages we had planted the garden to encourage bees etc into the garden, bought the bamboo type housing structures, with no evident usage and they pick our loft….
My question is, will those in the loft space, run the course, and eventually die / move on, or will this be a permanent re-occuring feature.
I really don’t have a problem with them to be honest. But being realistic, are they likely to increase in volume, and cause us any significant problems down the line.

I’ve had tree bumble bees nesting in the wall of the house since 2013. We notice the activity from May 2013 although there wasn’t much. I would say we saw a bee every 1 to 2 minutes. I was intrigued to know about the bumbles sharing my house and through this website identified them as tree bumble bees. In July 2013 we got a good look at them, as they must have got too hot in the nest and various large bees took turns to stand in the entrance of the nest and fan it. It’s a bit noisy when 2 or 3 are doing it at the same time.
By the end of August we didn’t see much activity at all and after looking at this website, found out that they finish around end of July.
I couldn’t find out if the nest would die and that was the end or if the queen would hibernate there and restart next year. Because we were unsure we left the hole in the wall, which incidentally is next to my cooker extractor fan flue.
I can tell you that the nest survives and must be bigger this year. We saw the bees coming and going from March 14. The traffic is much more than last year and is more a constant flow, every 5 seconds. Recently we noticed the nest surveillance. There are between 2 and 5 smaller bees flying around the entrance. Every so often they fly towards the bigger bees coming and going and we’ve seen a couple of them attach to each other and fly off. We’ve also seen a couple of these smaller bees dead on the floor.
I feel privileged to have them although my husband doesn’t agree. The more I find out the more i involve the children and when they see a bee out and about, they look very closely at the colours. They tell me they saw a bumble bee out, but it wasn’t one of ours!

Last year a friend had ‘bees’ around the roof of his shed. They turned out to be hypnorum and there was a nest under the roof tiles are about 15 feet up. This year he has reported a constant buzz of bumblebees hovering around the nest entrance. I am hoping to go and have a look at the end of the week. It sounds like male behaviour, but is it not too early? Also it is exactly the same nest site - I thought they did not use the same nest two years running? Allan

Great to read about other people’s experiences with the Tree bumblebee. We’ve had a colony in our loft space for the last 2 years, but this year we seem to have 2 colonies that are just separated by a chimney. There’s a lot of buzzing around and checking each other out it seems - certainly we are seeing more activity than in previous years!

My Dad also has a Tree bumblebee colony in a nest box and, after assuring him that they’re quite safe to have around, he seems to be quite enjoying watching them! The nest box is at about eye level, so you can get a really good look at them and their behaviour. One thing that I’ve found fascinating is that they appear to have largely blocked up the entrance hole, so that it is now much smaller and more “bee-sized”. Does anyone know what material they have used to do this? Also, when we watched them there were quite often 5 or 6 bees on the outside of the nest box constantly fanning their wings. Are they cooling the nest, (they seemed a bit far away from the entrance for it to do any good), or just on guard duty?

I have a B.hypnorum nest in a bird box and I noticed a couple of days ago that the entrance (which I had made smaller with a plastic tube) had been partially blocked with moss and old bird nest material from inside the box. On closer examination (up a ladder) I noticed a worker arranging the material and it left a small hole in the material about bee size. Presumably it makes the entrance easier to defend ?

I have a feeling that this nest maybe struggling as there are very low numbers coming and going from the nest box, and I see people on the forum already talking about male swarms. I am in South Wales though and the development of nests always seems a few weeks behind the South east and other regions, so I hope they do survive.